An investigation of capacity fading of manganese spinels stored at elevated temperature

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1838862· OSTI ID:289415

Inoue, Takao; Sano, Mitsuru ^[1]

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1. Nagoya Univ. (Japan). Graduate School of Human Informatics

The storage characteristics of a manganese spinel at various discharge depths and 80 C were examined in 1 M LiPF{sub 6} ethylene carbonate/dimethyl carbonate (1:2 by volume) electrolyte. The quantities of Mn dissolution and discharge-capacity loss were measured after the cathode at each discharge depth had been exposed to the electrolyte at 80 C. The quantities of dissolved manganese in the solution were less than 1.2% of the total manganese in all cathodes examined. Little capacity fading (3%) was found in the fully charged cathode, but a 59% capacity loss was observed in the fully discharged cathode. Correlations of the capacity loss with the X-ray diffraction peak widths were found, and the amount of capacity loss increased with broadening peak width. On the other hand, no correlation between the amount of Mn dissolution and the capacity loss was found. From these results, the authors propose a mechanism of the capacity fading of the spinel LiMn{sub 2}O{sub 4} stored at elevated temperatures as follows: lattice defects in the spinel due to Mn dissolution cause disordered crystal structures and as a result, the Li insertion-extraction paths are blocked, leading to capacity fading.

• Sponsoring Organization: USDOE
• OSTI ID: 289415
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 11 Vol. 145; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
36 MATERIALS SCIENCE
CATHODES
CRYSTAL STRUCTURE
DISSOLUTION
ELECTRICAL PROPERTIES
LITHIUM OXIDES
MANGANESE OXIDES
METAL-NONMETAL BATTERIES
VOLTAGE DROP